haruspex's latest activity

Because I could not be sure which you wanted and I felt it would be an easy mistake to make. But you seem to know what you are doing.

Yes, just be clear about which reference frame you want.

That is called coalescence. It is the case which maximises the lost KE and corresponds to coefficient of restitution = 0. Yes. In...

True, I was being lazy, which could mislead a student .I should have specified mechanical energy. Ah, no, that doesn’t do it because...

Yes, use momentum, but that is only one equation and you need two. Are you familiar with coefficient of restitution? That is a property...

Because you are specifying an impossible combination of conditions. In an actual one dimensional collision, there are two unknowns, the...

Your first calculation doesn’t assume "all the energy is transferred to the target". It assumes the target gets all the energy the...

Here's the animation from the wiki page: The effect is vastly downgraded, as the rope's expansion is on the same order of magnitude as...

The ant is always advancing to a new bit of rope, so it covers an increasing fraction of the rope. As that fraction increases, the...

Edit: only just saw @Ibix' solution. Seems to be even a very similar choice of variable names. The rope starts at length L and grows...

This is a common misconception. When you draw a force in an FBD, the direction shown only says which direction you are taking as...

It is called utility theory. Generally, the value one has for money is monotonically increasing but concave. The more you have, the...

Yes. because the hint says to take moments about P. Since the line of action of that force is through P, it has no moment about P...

I agree the collision example is ugly. First, it needs to be specified, symmetry wrt what? Let’s say it is the interchange of ##m_1##...

The Atwood example makes it clear what is intended. In that case, we should not expect the value of interest - the tension - to depend...